/*
 * Copyright 2002-2016 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.web.socket.sockjs.transport.session;

import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.sockjs.SockJsTransportFailureException;
import org.springframework.web.socket.sockjs.frame.SockJsFrame;
import org.springframework.web.socket.sockjs.frame.SockJsMessageCodec;
import org.springframework.web.socket.sockjs.transport.SockJsServiceConfig;

import java.io.IOException;
import java.util.Map;

/**
 * A SockJS session for use with polling HTTP transports.
 *
 * @author Rossen Stoyanchev
 * @since 4.0
 */
public class PollingSockJsSession extends AbstractHttpSockJsSession {

    public PollingSockJsSession(String sessionId, SockJsServiceConfig config,
                                WebSocketHandler wsHandler, Map<String, Object> attributes) {

        super(sessionId, config, wsHandler, attributes);
    }


    @Override
    protected void handleRequestInternal(ServerHttpRequest request, ServerHttpResponse response,
                                         boolean initialRequest) throws IOException {

        if (initialRequest) {
            writeFrame(SockJsFrame.openFrame());
        } else if (!getMessageCache().isEmpty()) {
            flushCache();
        } else {
            scheduleHeartbeat();
        }
    }

    @Override
    protected void flushCache() throws SockJsTransportFailureException {
        String[] messages = new String[getMessageCache().size()];
        for (int i = 0; i < messages.length; i++) {
            messages[i] = getMessageCache().poll();
        }
        SockJsMessageCodec messageCodec = getSockJsServiceConfig().getMessageCodec();
        SockJsFrame frame = SockJsFrame.messageFrame(messageCodec, messages);
        writeFrame(frame);
    }

    @Override
    protected void writeFrame(SockJsFrame frame) throws SockJsTransportFailureException {
        super.writeFrame(frame);
        resetRequest();
    }

}
